LONDON, 19 January, 2017 – Harvests in the United States are liable to shrink by between a fifth and a half of their present size because of rising temperatures, an international scientific team has found.

They say wheat, maize (known also as corn) and soya are all likely to suffer substantial damage by the end of the century. And while increased irrigation could help to protect them against the growing heat, that will be an option only in regions with enough water.

Their report, published in the journal Nature Communications, says the effects of a warming atmosphere will extend far beyond the US. But as it is one of the largest crop exporters, world market crop prices may increase, causing problems for poor countries.

Damaged crop

The lead author of the study is Bernhard Schauberger, from the Potsdam Institute for Climate Impact Research, Germany. He says: “We know from observations that high temperatures can harm crops, but now we have a much better understanding of the processes.”

The team compiled what they say was an unprecedentedly comprehensive set of computer simulations of US crop yields. The simulations were shown to reproduce the observed strong reduction in past crop yields induced by high temperatures.